There has been developed an IR-CCD imaging device which includes an array of IR detectors coupled to a CCD register which stores and transfers the signals from the detectors. Such a device is described in the article of W. F. Kosonocky et al., entitled "DESIGN AND PERFORMANCE OF 64.times.128 ELEMENT PtSi; SCHOTTKY-BARRIER INFRARED CHARGE-COUPLED DEVICE (IRCCD) FOCAL PLANE ARRAY" published in SPIE, Volume 344, Infrared Sensor Technology (1982) pp. 66-77. Although there have been improvements in such IR-CCD imaging devices in terms of numbers of elements of resolution and overall device size, a continual problem has been to achieve high fill-factors in order to provide the sensitivities required for certain applications of the imaging device. The term "fill-factor" refers to the ratio of active photo-sensing detector areas to the total area of the imaging cell. Areas of the device which are not used to sense signal, such as the CCD registers used to carry the charge, represent dead areas posing limitations on resolution and other system parameters.
One method to overcome these problems is to use a lenticular array structure to focus all the incoming signal onto the photo-sensing detectors. To properly mount a lenticular array on an imaging device raises a number of problems. One problem is to achieve proper alignment between the lenticular array and the detector areas of the imaging device. Another problem is to achieve uniform and accurate spacing between the lenticular array and the imaging device. Still another problem is to achieve a bond between the lenticular array and the imaging device which is strong enough to withstand the cryogenic (77 K.) temperature required to operate the infra-red arrays. Any bonding and spacing means must be around the edge of the lenticular array and imaging device in order that there is no obstruction to the passage of the imaging signal through the lenticular array into the imaging device. Although shims can be placed between the imaging device and the lenticular array to achieve the desired spacing, because of the limited area available to achieve both spacing and bonding, the shims must be of minimum size to allow sufficient area for the bonding needs.